查找部門有員工

Question

的最大數目我有一個表的員工

id name dept 
1 bucky shp 
2 name shp 
3 other mrk 

我怎樣才能讓員工的最大數目的部門（或多個）的名字？ ..

我需要導致

dept 
-------- 
shp 

Answer 1

假設你正在使用SQL Server和代表僱員的每個記錄。所以，你可以使用窗口函數來得到結果

WITH C AS (
    SELECT RANK() OVER (ORDER BY dept) Rnk 
      ,name 
      ,dept 
    FROM table 
) 
SELECT TOP 1 dept FROM 
(SELECT COUNT(Rnk) cnt, dept FROM C GROUP BY dept) t 
ORDER BY cnt DESC 

Answer 2

與普通表表達式，計算每個部門的行數，然後找到最大的數，然後用它來選擇最大的部門。

WITH depts(dept, size) AS (
    SELECT dept, COUNT(*) FROM employee GROUP BY dept 
), biggest(size) AS (
    SELECT MAX(size) FROM depts 
) 
SELECT dept FROM depts, biggest WHERE depts.size = biggest.size 

Answer 3

SELECT cnt,deptno FROM (
SELECT rank() OVER (ORDER BY cnt desc) AS rnk,cnt,deptno from 
(SELECT COUNT(*) cnt, DEPTNO FROM EMP 
GROUP BY deptno)) 
WHERE rnk = 1;